diff --git a/malloc/thread-freeres.c b/malloc/thread-freeres.c
index c71ca4fc33..3408bdbefd 100644
--- a/malloc/thread-freeres.c
+++ b/malloc/thread-freeres.c
@@ -21,6 +21,7 @@
 #include <resolv/resolv-internal.h>
 #include <rpc/rpc.h>
 #include <string.h>
+#include <tls-internal.h>
 
 /* Thread shutdown function.  Note that this function must be called
    for threads during shutdown for correctness reasons.  Unlike
@@ -32,6 +33,7 @@ __libc_thread_freeres (void)
   call_function_static_weak (__rpc_thread_destroy);
   call_function_static_weak (__res_thread_freeres);
   call_function_static_weak (__strerror_thread_freeres);
+  __glibc_tls_internal_free ();
 
   /* This should come last because it shuts down malloc for this
      thread and the other shutdown functions might well call free.  */
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c
index d16f3d71f8..4ae4b5a986 100644
--- a/nptl/allocatestack.c
+++ b/nptl/allocatestack.c
@@ -237,6 +237,8 @@ get_cached_stack (size_t *sizep, void **memp)
   /* No pending event.  */
   result->nextevent = NULL;
 
+  result->tls_state = (struct tls_internal_t) { 0 };
+
   /* Clear the DTV.  */
   dtv_t *dtv = GET_DTV (TLS_TPADJ (result));
   for (size_t cnt = 0; cnt < dtv[-1].counter; ++cnt)
diff --git a/nptl/descr.h b/nptl/descr.h
index e1c7db5473..6a509b6725 100644
--- a/nptl/descr.h
+++ b/nptl/descr.h
@@ -34,6 +34,7 @@
 #include <unwind.h>
 #include <bits/types/res_state.h>
 #include <kernel-features.h>
+#include <tls-internal-struct.h>
 
 #ifndef TCB_ALIGNMENT
 # define TCB_ALIGNMENT	sizeof (double)
@@ -398,6 +399,9 @@ struct pthread
   /* Indicates whether is a C11 thread created by thrd_creat.  */
   bool c11;
 
+  /* Used on strsignal.  */
+  struct tls_internal_t tls_state;
+
   /* This member must be last.  */
   char end_padding[];
 
diff --git a/string/strsignal.c b/string/strsignal.c
index 7e3b262c55..701ce20e6e 100644
--- a/string/strsignal.c
+++ b/string/strsignal.c
@@ -20,106 +20,36 @@
 #include <stdlib.h>
 #include <string.h>
 #include <libintl.h>
-#include <libc-lock.h>
-
-static __libc_key_t key;
-
-/* If nonzero the key allocation failed and we should better use a
-   static buffer than fail.  */
-#define BUFFERSIZ	100
-static char local_buf[BUFFERSIZ];
-static char *static_buf;
-
-/* Destructor for the thread-specific data.  */
-static void init (void);
-static void free_key_mem (void *mem);
-static char *getbuffer (void);
-
+#include <tls-internal.h>
+#include <array_length.h>
 
 /* Return a string describing the meaning of the signal number SIGNUM.  */
 char *
 strsignal (int signum)
 {
-  __libc_once_define (static, once);
-  const char *desc;
-
-  /* If we have not yet initialized the buffer do it now.  */
-  __libc_once (once, init);
-
-  if (
-#ifdef SIGRTMIN
-      (signum >= SIGRTMIN && signum <= SIGRTMAX) ||
-#endif
-      signum < 0 || signum >= NSIG
-      || (desc = __sys_siglist[signum]) == NULL)
-    {
-      char *buffer = getbuffer ();
-      int len;
-#ifdef SIGRTMIN
-      if (signum >= SIGRTMIN && signum <= SIGRTMAX)
-	len = __snprintf (buffer, BUFFERSIZ - 1, _("Real-time signal %d"),
-			  signum - SIGRTMIN);
-      else
-#endif
-	len = __snprintf (buffer, BUFFERSIZ - 1, _("Unknown signal %d"),
-			  signum);
-      if (len >= BUFFERSIZ)
-	buffer = NULL;
-      else
-	buffer[len] = '\0';
-
-      return buffer;
-    }
-
-  return (char *) _(desc);
-}
-
-
-/* Initialize buffer.  */
-static void
-init (void)
-{
-  if (__libc_key_create (&key, free_key_mem))
-    /* Creating the key failed.  This means something really went
-       wrong.  In any case use a static buffer which is better than
-       nothing.  */
-    static_buf = local_buf;
-}
-
+  const char *desc = NULL;
 
-/* Free the thread specific data, this is done if a thread terminates.  */
-static void
-free_key_mem (void *mem)
-{
-  free (mem);
-  __libc_setspecific (key, NULL);
-}
+  if (signum >= 0 && signum <= NSIG && signum < array_length (__sys_siglist))
+    desc = __sys_siglist[signum];
 
+  if (desc != NULL)
+    return (char *) _(desc);
 
-/* Return the buffer to be used.  */
-static char *
-getbuffer (void)
-{
-  char *result;
+  struct tls_internal_t *tls_internal = __glibc_tls_internal ();
+  free (tls_internal->strsignal_buf);
 
-  if (static_buf != NULL)
-    result = static_buf;
+  int r;
+#ifdef SIGRTMIN
+  if (signum >= SIGRTMIN && signum <= SIGRTMAX)
+    r = __asprintf (&tls_internal->strsignal_buf, _("Real-time signal %d"),
+		    signum - SIGRTMIN);
   else
-    {
-      /* We don't use the static buffer and so we have a key.  Use it
-	 to get the thread-specific buffer.  */
-      result = __libc_getspecific (key);
-      if (result == NULL)
-	{
-	  /* No buffer allocated so far.  */
-	  result = malloc (BUFFERSIZ);
-	  if (result == NULL)
-	    /* No more memory available.  We use the static buffer.  */
-	    result = local_buf;
-	  else
-	    __libc_setspecific (key, result);
-	}
-    }
+#endif
+    r = __asprintf (&tls_internal->strsignal_buf, _("Unknown signal %d"),
+		    signum);
+
+  if (r == -1)
+    tls_internal->strsignal_buf = NULL;
 
-  return result;
+  return tls_internal->strsignal_buf;
 }
diff --git a/sysdeps/generic/Makefile b/sysdeps/generic/Makefile
index bd4f9425ca..1240d99436 100644
--- a/sysdeps/generic/Makefile
+++ b/sysdeps/generic/Makefile
@@ -16,6 +16,7 @@
 # <https://www.gnu.org/licenses/>.
 
 ifeq ($(subdir),string)
+sysdep_routines += tls-internal
 CFLAGS-wordcopy.c += -Wno-uninitialized
 endif
 
diff --git a/sysdeps/generic/tls-internal-struct.h b/sysdeps/generic/tls-internal-struct.h
new file mode 100644
index 0000000000..33a9079ee9
--- /dev/null
+++ b/sysdeps/generic/tls-internal-struct.h
@@ -0,0 +1,27 @@
+/* Per-thread state.  Generic version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _TLS_INTERNAL_STRUCT_H
+#define _TLS_INTERNAL_STRUCT_H 1
+
+struct tls_internal_t
+{
+  char *strsignal_buf;
+};
+
+#endif
diff --git a/sysdeps/generic/tls-internal.c b/sysdeps/generic/tls-internal.c
new file mode 100644
index 0000000000..14b914e5f3
--- /dev/null
+++ b/sysdeps/generic/tls-internal.c
@@ -0,0 +1,21 @@
+/* Per-thread state.  Generic version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <tls-internal.h>
+
+__thread struct tls_internal_t __tls_internal;
diff --git a/sysdeps/generic/tls-internal.h b/sysdeps/generic/tls-internal.h
new file mode 100644
index 0000000000..1f6a117d76
--- /dev/null
+++ b/sysdeps/generic/tls-internal.h
@@ -0,0 +1,39 @@
+/* Per-thread state.  Generic version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _TLS_INTERNAL_H
+#define _TLS_INTERNAL_H 1
+
+#include <stdlib.h>
+#include <tls-internal-struct.h>
+
+extern __thread struct tls_internal_t __tls_internal attribute_hidden;
+
+static inline struct tls_internal_t *
+__glibc_tls_internal (void)
+{
+  return &__tls_internal;
+}
+
+static inline void
+__glibc_tls_internal_free (void)
+{
+  free (__tls_internal.strsignal_buf);
+}
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/tls-internal.c b/sysdeps/unix/sysv/linux/tls-internal.c
new file mode 100644
index 0000000000..6e25b021ab
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tls-internal.c
@@ -0,0 +1 @@
+/* Empty.  */
diff --git a/sysdeps/unix/sysv/linux/tls-internal.h b/sysdeps/unix/sysv/linux/tls-internal.h
new file mode 100644
index 0000000000..5d712abd4a
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tls-internal.h
@@ -0,0 +1,37 @@
+/* Per-thread state.  Linux version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _TLS_INTERNAL_H
+#define _TLS_INTERNAL_H 1
+
+#include <stdlib.h>
+#include <nptl/pthreadP.h>
+
+static inline struct tls_internal_t *
+__glibc_tls_internal (void)
+{
+  return &THREAD_SELF->tls_state;
+}
+
+static inline void
+__glibc_tls_internal_free (void)
+{
+  free (THREAD_SELF->tls_state.strsignal_buf);
+}
+
+#endif
